Battery and battery manufacturing method

Abstract

A battery includes: a battery outer case; an electrode body; and a terminal. The case main body includes a bottomed case main body which has a flat accommodation space and of which one surface is opened, and a sealing plate attached to that one surface of the case main body which is opened. The electrode body is a flat electrode body, is accommodated in the flat accommodation space of the case main body, and has a part to which the terminal is joined. The terminal includes a base end attached to the sealing plate, an intermediate part extending from the base end toward the part to which the terminal is joined, along a surface on one side of the battery outer case, and a tip end joined to the part to which the terminal is joined. The tip end of the terminal is joined to a surface on one side of the part to which the terminal is joined, and pushes the part to which the terminal is joined.

The invention claimed is: 
     
       1. A battery comprising:
 a battery outer case; 
 an electrode body; and 
 a terminal, wherein: 
 the battery outer case includes a bottomed case main body which has a flat accommodation space and of which one surface is opened, and a sealing plate attached to that one surface of the case main body which is opened; 
 the electrode body is a flat electrode body, is accommodated in the flat accommodation space of the case main body, and has a part to which the terminal is joined; 
 the terminal includes a base end attached to the sealing plate, an intermediate part extending from the base end toward the part to which the terminal is joined, along a surface on one side of the battery outer case, and a tip end joined to the part to which the terminal is joined; 
 the tip end of the terminal is joined to a surface on one side of the part to which the terminal is joined; and 
 in a state where an outer surface of the battery outer case is not constrained, that surface of the electrode body which is on an opposite side to a side where the tip end of the terminal is joined is pushed against the battery outer case more strongly than that surface of the electrode body which is on the side where the tip end of the terminal is joined. 
 
     
     
       2. The battery according to  claim 1 , wherein:
 the base end of the terminal is attached to the sealing plate, an attaching portion of the sealing plate being biased toward the side where the tip end of the terminal is joined; 
 the intermediate part of the terminal has a first linear part extending along the surface on the one side of the battery outer case, and a second linear part bent from a tip of the first linear part; and 
 the tip end of the terminal is bent from a tip of the second linear part, and has a flat shape having a thinner plate-thickness than that of the first linear part, and in a natural state where the electrode body is removed from the terminal, the tip end is inclined toward a side where the electrode body is attached. 
 
     
     
       3. The battery according to  claim 2 , wherein
 a boundary between the second linear part and the tip end has a base point at which the tip end is elastically bent relative to the second linear part. 
 
     
     
       4. The battery according to  claim 3 , wherein
 the second linear part is gradually reduced in plate thickness from the tip of the first linear part toward the tip end. 
 
     
     
       5. The battery according to  claim 3 , wherein
 a thickness of the boundary between the second linear part and the tip end is thinner than the other parts of the second linear part and the tip end. 
 
     
     
       6. The battery according to  claim 2 , wherein
 the base end and the first linear part of the terminal have rigidity higher than that of the tip end of the terminal. 
 
     
     
       7. The battery according to  claim 1 , wherein
 when an assembly in which the sealing plate, the terminal, and the electrode body are assembled is taken out from the case main body, that side of the electrode body which is far from the sealing plate is inclined relative to a normal line direction of the sealing plate, toward an opposite side to the side where the tip end of the terminal is joined. 
 
     
     
       8. A battery manufacturing method comprising:
 preparing a terminal; 
 preparing a flat electrode body; 
 preparing a case main body which has a flat rectangular-solid-shaped accommodation space and of which one surface is opened; 
 preparing a sealing plate to be attached to an opening of the case main body; 
 attaching the terminal to the sealing plate; 
 joining the terminal to the electrode body; and 
 placing, in the case main body, the electrode body out of an assembly including the sealing plate, the terminal, and the electrode body, and mounting the sealing plate to the opening of the case main body, wherein: 
 the terminal thus prepared includes a base end to be attached to the sealing plate, an intermediate part extending from the base end, and a flat tip end bent from a tip of the intermediate part, and the tip end is inclined relative to a normal line of an inner surface of the sealing plate such that, at the time when the terminal is attached to the sealing plate, a normal line of either one surface of the tip end intersects with a flat surface along the inner surface of the sealing plate; 
 in the joining of the terminal to the electrode body, the electrode body is joined to the one surface of the tip end of the terminal; and 
 in the placing of the electrode body in the case main body and the mounting of the sealing plate to the opening of the case main body, the terminal is deformed at a boundary between the intermediate part and the tip end, as a base point.